History
Blizzard Entertainment (Irvine, California) was founded in 1991 under the name Silicon & Synapse by Allen Adham (chairman), Mike Morhaime (president) and finally Frank Pearce (vice president).
They changed name to Blizzard Entertainment because, "no one knew what a synapse was anyway".
Blizzard developed several games before their first major hit that was Warcraft I. Predecessors are Rock 'n Roll Racing, The Lost Vikings, Blackthorne and The Return of Superman.
In 1996, Blizzard Entertainment acquired Blizzard North (San Mateo, California) that develops games on their own concurrently as "Blizzard South". Traditionally, Blizzard South has developed the "craft"-series like the Warcraft, Starcraft and World of Warcraft games while Blizzard North has focused on the Diablo world.
Milestones
Blizzard has a very large fan community and is also well-known for their good communication with their fans, shown by their now traditional open beta programs, where fans help Blizzard to test their games during beta stages.
Unfortunately, this honorable idea has recently resulted in problems with variations of software like bnetd such as the Warforge battle.net emulator.
Interestingly, Blizzard North also reinvented the roguelike game genre for commercial purposes that later became the game Diablo. Their ideas from roguelike games has been confirmed by Blizzard themselves.
Blizzard Entertainment are also proud maintainers of the world's largest free online gaming service Battle.net, with millions of registered users.
Fun Facts
Starcraft in space
A fan of Blizzard working for NASA has sent a copy of their highly successful computer game Starcraft into space, making Starcraft the first game in space in history.
Bill Roper and orcs
Bill Roper at Blizzard North can accurately speak in the Orc voice found in the Warcraft series without artificial help. He also made the voice of several Humans found in the Warcraft games.
The infamous Secret Cow Level
After several rumours of a Secret Cow Level in Diablo I (that of course wasn't true), Blizzard finally let go and added one in Diablo II.
Insider jokes
Blizzard often run insider jokes when naming characters and more. In Diablo II alone, there is monsters named Colenzo the Annihilator (after production manager Karin Colenzo), Shenk the Overseer (after lead character artist Phil Shenk), Lord de Seis (after lead programmer Rick Seis) and who know how many more?
Additionally, the monsters called The Fallen shout "Dashow!" as a war cry after character artist Michael Dashow.
A place called the Halls of Vaught are named after background artist Fredrick Vaught.